Nec Corporation

Satoshi Sonobe

Hiroaki Nakajima

Yoshitaka Nakao

Hideyuki Muto

Kentarou Kudou

Shunichi Kumagai

In order to provide a communication system and the like which are capable of updating a correction value of a time synchronization packet, and to which a traffic bonding scheme is applied, a set of primary devices of the communication system determines presence or absence of communication in a first transmission path, adds an actual measurement value of a first delay amount to an information value when a determination result according to the determination is that the communication is present, or adds, to the information value, a design value of a second delay amount being the delay amount inside the wireless transmission device and the wireless reception device when the determination result is that the communication is absent.

Communication system, communication method, and communication program

A wireless communication apparatus () includes: a switching control unit () that determines an active mode wireless communication apparatus at an opposite side based on a failure occurrence status of an active mode wireless communication apparatus at the opposite side under a situation that the wireless communication apparatus () is in the active mode; a wireless transmitting unit () that transmits a switch instruction to the opposite side under the situation that the wireless communication apparatus () is in the active mode, the switch instruction instructing the active mode wireless communication apparatus at the opposite side that is determined; and a wireless receiving unit () that receives the switch instruction from the opposite side, wherein the switching control unit () switches the wireless communication apparatus () to one of the active mode and the standby mode based on the switch instruction received from the opposite side.

Wireless communication system, wireless communication apparatus, and wireless communication method

In order to improve efficiency of data transmission in a wireless transmission band under a condition in which both adaptive modulation scheme and FDD scheme are employed, and fixed rate signals and a variable rate signal are multiplex-transmitted, one wireless transmission device (_) multiplexes a plurality of fixed rate signals (FS_to n) and a variable rate signal (VS) to generate a frame (FR), and sends the frame (FR) to another wireless transmission device (_) through a wireless transmission path (CH). At this time, the device (_) includes, in the frame (FR), information (MN) relating to a number of multiplexed fixed rate signals. The device (_) multiplexes a plurality of fixed rate signals (FS_to n) and a variable rate signal (VS) to generate a frame (FR), and sends the frame (FR) to the device (_) through a wireless transmission path (CH) having a different frequency. At this time, the device (_) determines a number of multiplexed fixed rate signals in the frame (FR) according to the information (MN).

Wireless transmission device, wireless transmission system, and method for controlling wireless transmission device

A data transmission apparatus includes: a transmission data division unit which divides transmission data into blocks; a transmission unit which transmits the blocks divided by the transmission data division unit to the transmission destination apparatus; a calculation unit which calculates a size of residual data generated by dividing the transmission data into the blocks each having the predetermined data size; and a residual data judgment unit which judges whether the size of the residual data calculated by the calculation unit is smaller or not smaller than a minimum data size which the receiving apparatus can receive. In the case that it is judged that the size of the residual data is smaller than the minimum data size, the transmission data division unit generates a block, which includes the residual data and whose data size is equal to or larger than the minimum data size, by dividing the transmission data so as to make the block, which includes the residual data, include a part of the transmission data other than the residual data.

Data transmission apparatus, data division apparatus and data division method

[Problem] The problem is to carry out the QoS control which tracks a change in a state of an outward line. [Means for solving the problem] A network repeater according to the present invention includes: a flow control means to carry out flow control for restricting inflow of a data flow which is received through an inward line; a bandwidth control means to carry out bandwidth control of controlling a bandwidth of a data flow which is received through the inward line and is sent through an outward line; and an outward line monitoring means to monitor a change in a state of the outward line. In the case that the monitored state of the outward line satisfies a specified condition which is determined in advance, either the flow control or the bandwidth control is carried out on a condition corresponding to the specified condition.

Network repeater, QoS control method and storage medium storing QoS control program

A wireless network relay apparatus includes a Layerswitch and a line control device as well as wireless/wired line terminating devices performing band limitation associated with an AMR function. It measures traffic passing through each line terminating device in inflow/outflow path directions. Upon detecting a modulation scheme changed due to an AMR function in a wireless area, it may specify a line terminating device so as to read a desired modulation scheme from a transmission source modulation scheme conversion table of the line control device based on traffic. It may change a local modulation scheme with a desired modulation scheme when a difference therebetween is above a predetermined number of stages. By tracking a modulation scheme changed for a transmission destination, it is possible to appropriately change a modulation scheme for a transmission source, thus suppressing traffic without discarding necessary data.

Growing community of inventors

Tokyo, Japan

Satoshi Sonobe